Embodiments of the inventive concepts disclosed herein are generally directed to airborne systems and methods for detecting and avoiding atmospheric particulates, and more particularly, but not by way of limitation, to airborne systems and methods for detecting and avoiding volcanic ash, ice crystals, and other atmospheric particulates in a flight path of an aircraft.
Atmospheric particulates such as volcanic ash plumes or clouds, ice crystals, smoke, dust, or other particulates suspended, dispersed, aerosolized, or otherwise present in the atmosphere occur naturally, typically originating from volcano eruptions, dust storms, forest and grassland fires, vegetation, erosion, sandstorms, tornadoes, or other natural sources. Examples of human activities which are sources of atmospheric particulates include the burning of fossil fuels in vehicles and power plants, various industrial and agricultural processes, controlled burns, and space vehicle launches.
Atmospheric particulates represent significant hazards to continued safe operation of aircraft when such atmospheric particulates are present in the aircraft's flight path and are encountered by the aircraft. In some cases, atmospheric particulates such as volcanic ash encountered by an aircraft during flight may enter the engines or avionic systems of the aircraft and may cause damage, extensive wear, and in some cases may even lead to complete engine shutdown, inoperable avionic systems, or other malfunctions resulting in flight emergencies and increased operation and maintenance costs.
Volcanic eruptions are the main source of atmospheric sulfur dioxide (SO2, a toxic gas with a pungent rotten odor). Accordingly, the presence of increased SO2 concentrations may be correlated with or interpreted as an indication of the potential presence of volcanic ash in the vicinity of the area with increased SO2 concentrations. However, because SO2 and volcanic ash disperse differently in the atmosphere and are not always co-located after a volcano eruption, increased atmospheric SO2 concentrations are typically combined with other factors (e.g., visual observation, reported sightings of ash plumes, known volcano locations or eruptions, lightning strikes, satellite imagery) to evaluate the presence of volcanic ash. In the past, increased SO2 concentrations were generally detected by flight crews by smell, i.e., after the aircraft had already encountered the increased SO2 concentration.
As another example, ice crystals encountered during flight may stick to, coat, or otherwise accumulate onto aircraft control surfaces or avionic system sensors or ports and may cause a variety of problems including compromised flight characteristics or inaccurate avionic system readings or complete system failures.
To ensure aircraft safety, currently applicable International Civil Aviation Organization (ICAO) rules specify that pilots avoid flying into visible clouds of volcanic ash. Further, while some aircraft are equipped with heaters and other devices allowing aircraft to fly into know ice, most aircraft avoid flying into known accumulations of ice crystals.
While higher density clouds, plumes, or accumulations of volcanic ash or other atmospheric particulates are generally visible to flight crews during clear weather and daylight conditions, even higher density clouds of atmospheric particulates may not be easily visible or may be practically visually undetectable during night, low light, inclement weather, or other reduced or compromised visibility conditions. Further, lower-density atmospheric particulates which are practically invisible even under optimal visibility conditions present significant dangers to continued safe operations of aircraft, because damage caused by atmospheric particulates is cumulative and is a function of the total mass or total mass load of atmospheric particulates encountered by the aircraft. The total mass of atmospheric particulates encountered by the aircraft depends on both the density and the total area of the encountered atmospheric particles. For example, relatively low-density clouds or other accumulations of atmospheric particles encountered over a relatively larger portion of the flight path of an aircraft may cause the same or similar damage to the aircraft as relatively high-density clouds or other accumulations atmospheric particles encountered over a relatively smaller portion of the flight path.
To enhance aircraft safety and reduce the likelihood of aircraft encountering atmospheric particulates, satellite imaging has been used to detect volcanic ash with limited success due to inherent limitations which make satellite imaging impractical for this purpose. For example, because satellite imaging is top-down imaging, satellite imaging is significantly hindered or rendered impossible by interferences from meteorological clouds which may obscure or conceal atmospheric particulates from the vantage point of the satellite. Further, there is no feasible way to accurately measure the vertical dimension (e.g., the height) of atmospheric particulates via satellite imaging due to the top-down vantage point of the satellite relative to the atmospheric particulates.
Another issue that limits the use of satellite imaging for detection of atmospheric particulates is that satellite imaging data is typically transmitted to a control center, which then processes and interprets the imaging data to determine the presence and location of atmospheric particulates. Various algorithms use satellite imagery and a variety of parameters which are integrated over the area covered by the atmospheric particulates to infer the total mass and mass loading of a particular cloud or accumulation of atmospheric particulates. The total mass and the mass loading are quantifiable products of the analysis and are integrated with various atmospheric particulates dispersion models to generate risk maps for use by the aviation industry.
Once this processing is complete, the control center relays the risk maps and other relevant information to aircraft in the vicinity of the detected atmospheric particulates, which introduces a delay between the time the satellite imagery was initially obtained and the time the atmospheric particulate information is provided to flight crews. This inherent delay may cause an aircraft to encounter atmospheric particulates prior to the information being relayed to the aircraft, or because connectivity with the control center is intermittent or lost. Further, as atmospheric particulates often move or disperse due to winds in the atmosphere, this delay may result in inaccurate information being relayed to the aircraft as atmospheric particulates may have moved, dispersed, and/or the density, total mass, or mass loading of the atmospheric particulates may have changed since the satellite imaging data was originally captured. The inaccurate information may cause aircraft flight paths to be unnecessarily altered, resulting in increased operating expenses, or may result in the aircraft unexpectedly encountering atmospheric particulates which have moved beyond the reported or expected position or location.
Accordingly, it would be advantageous to provide aircraft with an airborne system configured to detect atmospheric particulates in the flight path of the aircraft, determine the hazard level of the atmospheric particulates, alert flight crews of the potential encounter, and assist flight crews in avoiding the atmospheric particulates by altering the flight path of the aircraft as appropriate. It is to such system and methods of using thereof that embodiments of the inventive concepts disclosed herein are directed.